Research in the Healey lab is focused on the neural basis of natural behavior. We study songbirds as our research model for understanding vocal learning and brain plasticity. Over 50 years of intensive study of songbird behavior and brain function have provided a detailed roadmap of the neural circuits that are involved in singing, song learning, and audition (see diagram below). Our lab is interested in how neural circuits for vocal communication are modulated by the actions of local neurochemicals. For example, changing levels of brain estrogens can alter the pattern or 'tone' of neural circuit activity, enabling many flexible outputs from the same circuit. We think this modulation allows interconnected forebrain circuits to subserve a wide variety of complex behaviors, like singing, song learning, and song memory.

The song motor pathway
contains circuits that directly pattern song output. Incoming sensory information is processed by HVC, and HVC initiates motor sequences that project out to the peripheral vocal organ, the syrinx, via RA and the hindbrain nucleus nXIIts.
The auditory pathway: contains circuits that process sounds, including song. Auditory signals enter the brain at the cochlear nucleus (CN) and are further processed as they pass through the forebrain by nuclei such as NCM and CM.
The forebrain loop pathway contains circuits that are important for song learning and song variability. HVC sends projections to a basal ganglia loop (striatal-thalamic-cortical-striatal) which has an important output projection to the song motor pathway at nucleus RA.